Safety fuse



March 2 1926. 1,574,870

c. D. CUNY ET AL SAFETY FUSE Filed April 8', 1924 Patented Mar. 2, 192.6.

GFFICE.

CLIFFORD D. CUNY AND HOWARD W. JOHNSON, OF WASHINGTON, DISTRICT OF COLUMBIA.

SAFETY FUSE.

Application filed April 8, 1924. Serial No. 704,992.

To all whom it may concern:

Be it known that we, CLIFFORD D. CUNY and HOWARD lV. JOHNSON, citizens of the United States, residing at l Jashington, District of Columbia, have invented certain new and useful improvements in Safety Fuses, of which the following is a specification.

This invention relates to certain improvements in safety fuses for protecting electrical circuits and devices generally, and has for its primary object to provide a safety device to be used in conjunction with the terminals of an electric fixture such as a lamp and its corresponding socket, and so arrange the safety device that it will be positive in action in disengaging thelamp or the like from electrical contact with its socket.

With the foregoing and other objects in view the invention consists in the combination of parts and the details of construction hereinafter described and claimed, and illus trated in the accompanying drawings, in which Figure 1 is a diagrammatical view in front elevation of a lamp;

Figure 2 is a vertical section through the lamp socket, and the safety fuse in assembled position;

Figure 3 is a vertical section through the socket, and its insulating cup and spring in the dissembled position assumed when the fuse has been fused.

Referring more particularly to the drawings, Figure 1 represents lamp or the like with a bulb 1, base 2, and terminals 3.

Figure 2 shows the assembled construction in operative position. A suitable base 4 is provided with a socket 8 to receive the terminal 3 of the lamp. A. cup-shaped member 5 of insulating material and provided with a circular flange 5 is placed in the socket 8. Cup 5 is of such size as to snugly receive the terminal 3.

A coil spring 6 is arranged about the cup 5, and between the flange 5 and the bottom of the socket 8. A second coil spring 9 is arranged about the terminal 3, and between the flange 5 and the base 2 of the lamp. In order to assemble the device as shown in Figure 2, a downward pressure is exerted on the base 2 of the lamp until the springs 6 and 9 are compressed to the desired ex tent. A, suitable fusible and electrically conductive material 7, such as solder, is then poured in a molten condition, in such a mannor as to retain the two springs in compressed position. The electric current is now allowed to pass from the socket 8 to the spring 6, through the fusible material 7, thence to the spring 9, and to the terminal 3. While we have described but one terminal, it will be understood that all of the terminals 8 may be thus provided for.

The composition of and the amount of fusible material applied is predetermined in accordance with maximum amount of voltage desired. When this current is exceeded, the material 7 becomes fused, allowing both springs to expand, resulting in terminal being forced upwardly from the cup 5 by the action of the spring 9 and also by the ac tion of the spring (5 in forcing the cup upwardly and away from the socket S, as shown in Figure 3.

This effectively breaks contact and is advantageous over the conventional fuse in that when, in our device, the fusible mate rial is fused the action of the springs insures a positive and immediate breaking of contact. It is further contended that we have provided more than a resilient means for insuring this desired result, in that we have provided a novel arrangement of insulation, springs, and the fusible material.

We claim 1. In combination with a terminal and its corresponding socket, a fuse comprising a tubular body of insulating material arranged in said socket, fusible material extending from said socket to said terminal, and resilient means for positively disengaging said terminal from electrical contact with said socket when said fusible material becomes fused.

2. In combination with a terminal and its corresponding socket, a safety fuse comprising a tubular body of insulating material, placed in said socket, and having a flange at its upper end, said terminal being an ranged in said body and having a coil spring attached thereto, said spring bearing on said flange and being under compression, a secininal from electrical contact with said 0nd 0011 spring surrounding said insulating socket when said fusible material becomes body and bearing upwardly on said flange fused.

and downwardly on said socket under com- In testimony whereof we afiix our signa- 5 pression, a strip of fusible material connecttures.

ing said springs, said springs being adapted CLIFFQRD CUNY.

to expand and positively disengage said ter- HOVA'RD W. JOHNSON. 

